USSR Japan Joint Cooperative Geophysical Survey on Japan Sea 1990-1991Principal Investigators :Hajimu KINOSHITA Earthquake Research Institute, University of Tokyo, Tokyo, Japan (ERI) andBoris Yakovlevich KARP Pacific Oceanological Institute, Acadmy of Science, Vladivostok, CIS (POI)Participating Institutions and Universities (Japan) :Earthquake Research Institute, Ocean Research Institute (ORI), Department of Earth and Planetary Physics, University of Tokyo. Department of Geophysics, Hokkaido University. Department of Earth Sciences, Kobe University. Department of Marine Sciences, Tokai University. Department of Geology, Kochi University. Department of Earth Sciences, Kumamoto UniversityInitialization of this joint program was conducted by three scientists ; Prof. S. Uyeda (ERI), Dr. B. Y. Karp, and Prof. T. W. C. Hilde (Texas A&M Univ. Texas, USA). An agreement that Japan and USSR are to conduct joint geophysical surveys in the Sea of Japan was finally concluded between ERI and POI.Pr
… Moreogram of 1990 Fiscal Year : the first phase of the joint study was begun with exchanges of data, knowledge, as well as scientists from both sides for obtaining basic geophysical data of the Japan Sea available so far. Exchanges were performed twice, first meeting at ORI and second at POI, CIS. In the summer, both institutions, ERI and POI, sent out research vessels, Tansei-maru [ORI], with two scientists from CIS aboard) and Prof. Bogorov, (POI, with three scientists from Japan) to perform seismic reflection, seismic refraction, and marine magnetic surveys. In this expedition, both research vessels met out on sea to calibrate positioning capability with each other and returned to the survey area assigned to them. After stationing 26 sets of Ocean Bottom Seismographs (OBS) across Exclusive Economic Zone Boundary (EEZ), long distance dynamite shots were fired from Japanese Zone. Of 26 sets of OBS, 6 sets were deployed by CIS. Data processing and readjustment were done in cooperation with POI scientists mostly in Japan using facilities of ERI, ORI, as well as Chiba University after confirming ship positions and refinements of OBS data which were digitized and rearranged by using high speed computers. All the processed data of positioning, seismic and magnetic measurements were resorted and distributed to all the participating members upon their requests.Program of 1991 Fiscal Year : the way of cooperative work among those who participated this program was much the same as those of previous fiscal year. This time, Japan sent again Tansei-maru and CIS sent Prof. Gagarinski. However, the cruising periods of these research vessels could not be adjusted in a way that both of them were out on sea at the same time. This is caused partly due to a fact that in spite of agreement between Japan and CIS by the 5-th Session of USSR-Japan Commission On Science-Technology Cooperation held in November, 1990 in Tokyo, that we are allowed to do oceanological joint surveys beyond EEZ border, application for conduction of the proposed experiment was not accepted by CIS. Therefore, Tansei-maru (with no CIS scientists) conducted again OBS and seismic reflection surveys in the vicinity of the survey area of previous year. Instead, Prof. Gagarinskii (with tow Japanese scientists on board) conducted magnetic and gravimetric surveys in the western part of the japan Basin (i. e., northwestern part of the Japan Sea).The results are published in several publications, presentations on meeting or symposium of scientific societies of Japan as well as abroad. Entire volume on the present issue will be printed separately in a near future. Less